The use of medical ultrasound, to image the median nerve, is not considered a new diagnostic tool however, the use of portable units with high frequency transducers and power Doppler are an innovative non-invasive alternative for monitoring musculoskeletal disorders occurring in the workplace. Further exploring the potential of using ultrasound as a health surveillance tool for monitoring the health of the median nerve in workers in occupations that are higher risk for CTS is also innovative. Therefore, the central hypothesis of this proposal is that medical ultrasound with high frequency transducers and power Doppler can provide surveillance of the median nerve and document development and recovery of CTS. This will be explored using a volition animal model to determine whether the use of Doppler, gray-scale imaging, and a combination of exams (EDX, MRI and ultrasound) can follow pathologic changes in the median nerve from baseline to end exposure through recovery. Power Doppler has the ability to record acute changes such as hyperemia and increased blood flow in the perineural arterioles. Gray-scale Doppler has the ability to record chronic changes to the median nerve associated with median mononeuropathy (MMN). An ischemic narrowing or "notch sign" signifies the demyelination of the nerve. Lastly MRI and EDX are tests that are difficult to perform in the workplace however they are considered a clinical standard and it is important to trend the ultrasound data against these measures in the 8 macaca fascicularis that are moving from baseline to recovery of MMN. This project will help to accelerate the use of ultrasound to provide both non-invasive and affordable diagnostic information in the workplace. PUBLIC HEALTH RELEVANCE: The translational impact of this experiment will be to verify that ultrasound is a non-invasive imaging technique for surveillance of MMN that progresses due to repetitive wrist-hand tasks. Previous work has been mitigated by human subject's involvement in contributory activities outside of the workplace. This study will allow for an assessment of the progression of MMN and the utility of using portable ultrasound as a dynamic and sensitive means for tracking median nerve pathology.